Valves and Piping

Corrosion of reactors used for functionalization and ia pipes and valves along transferlines for sulfuric acid is a problem that results ia maintenance shutdowns. Sufficient agitation is needed to keep the resia beads fluidized duting sulfonation. As for copolymer kettles, transfer lines should be sufficiently large to allow reasonably rapid transfer of Hquids and resia slurries. 

Utilize double block and bleed pipe and valving system... 

Safe operation is generally assisted by simplifieation of piping and valve arrangements, and by their identifieation, e.g. by eolour eoding or tags. Logieal arrangement ean also serve as a prompt in identifieation. 

Solvent reeovery systems would also neeessitate the speeifieation of eondenser duties, distillation tower sizes, holding tanks, piping, and valves. It is important to note that the engineering design of an adsorption system should be based on pilot data for the partieular system. Information ean usually be obtained direetly from the adsorbent manufaeturer. The overall size of the unit is determined primarily by eeonomie eonsiderations, balaneing the operating eosts against the eapital eosts. 

Process systems handling polymers and resins (e.g., butyl rubber or ethylene-propylene diene monomer rubbers) are often subject to plugging at dead-end locations such as PR valve inlets. In extreme cases, complete blockage of inlet piping and valve nozzle can result. This problem can be eliminated by the application of a flush-seated PR valve, in which dead-end areas are eliminated by placing the valve disc flush with the vessel wall, in the flow pattern of the contents. 

The C values for different types of resistances are available in hydraulics textbooks and also from the literature of pipe and valve manufacturers. 

In order to cover all the lines in the facility, pipe and valve tables are normally included. Each pipe pressure class is assigned a designation. Sometimes it is necessary to assign two classes for a single designation. For ample, in Table 15-1 A, L, and AA are all ANSI 150 cl , but they contain different fluids. 

Condenser Controls. .Miscellaneous (Condensing System). Circulating Water. System. Condensate Sysrem. . Pumpa, Piping and Valves. .Low/Tnter. Press- Heater/Oeaerators 3350-3352. .Polishers/Chemical Addle Ion 3360-3399. .Miscellaneous (Condensate System) 3901-3999. Feedwater System 3501-3509. Heater Drain Systems 3520-3529. Entractlon Steam. Electrical. Auxiliary Systems. .Service Water (Open System)... 

Cooling water required on site often is stored in towers storage tank problems or piping and valve malfunctions could cause loss of this component. If seawater is used, materials of construction must be more resistant to salt. Loss of steam purchased or generated in water tube boilers could result from boiler lube failure, turbine failure, or piping or valve malfunction. 

Typical pipe and valve failures and tlie reasons for tlieir occurrence are discussed by Kletz. The paragraphs tliat follow give some examples. 

The flow rate needs to be 20 gpm. Connections of pipe and valve are flanged, with the 6°-90° elbows added in the line. 

Aq and Ay, are the areas of the pipe and valve throat, respectively, at a particular point in the valve opening range. As with the velocity and pressure at the throat, the area Ay cannot usually be measured. However Oy is also related to the upstream cavitation index Oq when the flow in the valve is choked . In the valve context this is the condition which exists when further reduction of the downstream pressure fails to increase the flow through the valve. The value of Oy is given by the expression ... 

Although plastics may not be as hard as metal products, there are those that have excellent resistance to wear and abrasion. Plastic hardware products such as cams, gears, slides, rollers, and pinions frequently provide outstanding wear resistance and quiet operation. Smooth plastic surfaces result in reduced friction, as they do in pipes and valves. 

The FW supply system is part of the pre-boiler section, as is the pretreatment plant. It includes all necessary distribution pipes and valves, the boiler FW regulator, FW pumps, FW tanks, and various forms of FW heaters. 

Colors in a laboratory should be coordinated, just as in a home. If pre-finished work benches are to be installed, they might set the color scheme. While they are available in several colors or combination of colors, the choice is not unlimited. In one case, the laboratory operator was color blind, so his wife took over the job as decorator. First, she selected a two-color scheme for the work benches. Color chips in hand, she then chose a floor covering from a number of samples submitted. For the wall paint, she found a standard color of the recommended quality that harmonized with the cabinets. A few appropriate charts and a colorful cloth wall-hanging of pipes and valves completed the decor. The result received many favorable comments from visitors to the facility. 

It should be noted that plastic pipes and valves used for DI water have limited structural strength and must be well supported by straps and brackets. 

One problem was ensuring that the outer door was closed before the inner door was opened. Because no direct visible check was possible, a small pipe and valve were attached to the top of the torpedo tube in the torpedo room. Before opening the inner door, the valve was opened momentarily to check for the presence of pressurized water in the tube. The presence of pressurized water was a direct indication that the outer door was open. 

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